Potassium chloride as ground improvement in quick clay areas – a preliminary study

Abstract

Potassium chloride was added to low saline Norwegian post glacial clays to study its effect on strength parameters. The laboratory study was carried out on undisturbed sensitive clay samples from two locations in mid-Norway. The mechanical behaviour of sensitive clays is greatly influenced by their pore water ionic content. Adding salt changes the geotechnical properties of quick clay to such an extent that it appears as a total different clay. Salt migration is a time consuming process strongly dependent on diffusion through the soil. Deriving the effective diffusion coefficient from water content of 30–50 %, the clay will be de-sensitized over a length of 50 and 56 cm respectively after 1 year. Ground improvement with salt is done by installing salt wells. This study is part of a design project for such installations. The consumption of time depends on the distance between the wells, diffusion coefficient and maintenance of high concentration in the salt well.